Balanced-drive swiveled-cutter hobbing machine



Oct. 12, 1926. 1,603,258

' W. F. ZIMMERMANN BALANCED DRIVE SWIVELED CUTTER HOBBING MACHINE Filed June 16, 1924 2 Sheets-Sheet l il/ghl.

WTM

Oct. 12, 1926.

W. F. ZIMMERMANN v B A LANCED DRIVE SWIVELED CUTTER H GBBING MACHINE 2 Sheets-Sheet 2' Filed June 16, 1924 wan-alumni,

avwcmtoz WILLIAM F. ZIMMERMANN, oF'MArLEwoon; NEW JERSEY, ASSIGNOR o GOULD &

Patented Oct. 121, 1926. I

EBERHABDT, DIE-NEWARK, NEW JERSEY, CORPORATION OF NEW JERSEY.

BALANCED-DRIVE swIvELnn-cn'rTEn. I-IIOIBBING 'MACEINE.-

' Applieatieii filed Ja e; 924. s narn 720,393;

This invention dealsWith machines for.

generating gears bythecutting action of a so-called hob.andthe primary ob]ect is to so organizedas to contribute to vvards'the attainment of a high degree oi accuracy in the machine, While 'yet' providing sufficient.

adaptability to produce'either spur gearsoi diflerent pitches and a fairly Wide range in the number ofteetlnor helical gears of a given angle and. dilferent pitches and a fairly Wide range in'the numbers jof teeth;

all without sacrificing the advantages' of. a balanced driveYbetW'een the prime mover and the respective spindles.f p

In my Patent #1,4' 72,767-, there is shown.

a machine based'on a simplified and symmetrlcal. arrangement which practlcal usage has demonstrated to ,be highly accurate, sturdy and suitable for intensive' productionf of gears Within its range; such machine per 'haps being most suitable for producing.

spur-gears of a single-pitch and a limited range in numbers of'teeth;

Theobjective of thisinvention is so to improve that organization that the machine will be .materially extended. in ,range, as: above stated, While yet adhering in a pro-; nounced measure to the advantageous pr nciples of construction and, arrangement pointed out in my a'toresaid patent; all as will appear more clearly hereinafter.

Fig. 1 is a perspective of a machine embodying my improvements; Fig. 2 isla diagram in plan of its transmission system and i Fi 3 is a dlagramln elevation of the same.

The invention contemplates two spindles arranged transverselyrone being utilized as a hob-su 'i 'iorting spindle,- repres nted. by" 1. and the other being utilized as a Work-supporting spindle represented by 2. .These spindles are appropriately mounted; as for example, in the heads indicated by 3 and 4 respectively. 'The hob-supporting spindle is, however, so secured to the head 3 that it:

I may be swiveled to a, limited extent and thereby set at a slight angle, on the head.' But this limited tiltability is accomplished.

in a manner intimately related to and contributingto the attainment of abalanced drive of the spindles through the agency oi; v the minimum number of anglegears; This, will beexplained lateribut here itmay be notedthat onthehead'g is a spindle bear 3O hich; instead. of being'centrally p'ivotedto the. head, has an off-set pivot coaxial With the intermediate angle-gears g e thatfco'nvey the motion from the angle gear as on the shaft 14w that on the spindle 1. Arcuate slots 31 and appropriate bolts :32 a'c'compl1shthis function; the radii of said slotsbeing centered uponthe axis of the in-:

termediate angle-gears 3 :e.

and the partsivill be so arranged as to permit of a so ealled teed; i. e.,'relative trans-y I lation between the respective spindles hile ftheyare rotating. 'It is immaterial Whether.

thisrelative 'fe ed' be obtained bythe absolute translation of the cutter-supporting spindle or bythe absolute translation otw the work-supportingspindle and it is like- Wise imniaterialivhich of these spindles be arranged verticallygthe important consideration being that they are transverse to one another and that provision is made for an) offset mountingjon the axis of the. cutter-.

supporting spindle with respect to the axis of the. Work-supporting spindle so that the teeth of the hob Willoperate on the periplr V ery'of the blank; When it is desirabletot." use the machine for cutting diilerentdiameters of gears, it islessential to provide for an ad uStment of the atoresaid offset relation and thatinayzconveniently be attained in the manner illustrated by the embodiment of the V inventiondepictedby Fig. l in Which the I carriage a is adjustable along the slide 6 provided by the body-portion 7 of the machine;

a scre'w shaft such as 8, of conventional con struction, being available for facilitating the adjustment. The relative translation or :feediis likewise obtained by providing for corresponding travel either of the'blank spindle in the direction of its axis or, as

shown by 'Way of example by F 1, of the.

cutter-spindle transversely to its axis. "In the lattercase the stanchion S of theinachine provides a slideWay 9 extending parallel Withthe. axis of the ivorlc'supporting spindle; andthe head 3 (on which the cutter spindle l is sWivelly journaled). is caused'to travel. along thefslidewayh; this action being performed. in a conventional manner by" means of anordinaryteed-serewflO deriving i motion in anyg. appropriate .manneni.

these means, the hob 11 is caused bodily to be shifted in'a direction parallel with the axis of the work-supporting spindle during the process of generating the teeth on the blank. I f 7 This invention contemplates not more than three long transmission shafts in the trans mission determining the relation between the rotations of the cutting-spindle and the rotations of the work-supporting spindle, and it proposes to mount and arrange such gears and shafts as are actually employed in a manner affording a very high degree of precision in the construction and performance of the machine. Very important, likewise, is the cl'iaracteristic of this invention which resides in the employment of a single powerdriven intermediate-shaft arranged in equalized relation to the two spindles, respectively, so that the propelling force will flow from approximately a midpoint in opposite directions to the respective spindles through six angle gears only to the hob-spindle, and through a balanced number of gears only (i. e. six). to the work-spindle. Uf' these two sets'of six gears, one pair of the one set extends the ran e of the machine b makin it b provision for swiveling the hob-spindle to a limited extent, and one pair of'the other set makes provision for extending the range of relative rotations between the spindles; these two pairs being balanced against each other and'thus jointly increasing the range of the machine and adapting it to produce either spur gears of different pitches and a fairly wide range in the number of teeth,

' o r helical gears of a given angle and different pitches and a fairly wide range in the numbers of teeth. This characteristic of construction will best be understood by referringto the drawings in' which A indicates the intermediate long power-driven shaft in 'balancechdrive relation between the respective spindles. This shaft derives its motion, in the first instance, from a suitable primemover 12, as by means of suitable gearing 13, the specific character of which is unimportant. The power is taken from the shaft A at two separated points and flows in opposite directions to the respective spindles. A noteworthy characteristic of the arrangement is that the intermediate shaft A carries two distinctive species of gears, to wit, a bevel-gear B and likewise a spur-gear C; these gears being preferably rigidly secured "to the shaft A and spaced apart thereon so ywith which the relatively long shaft A may 1 be accuratelyjournaled. In'the'form shown by Fig. 1 the bevel-gear B (which is to be regarded as representing an optional species of right-angled gear-drive) delivers the mo tion for rotating one of the spindles, while the spur-gear C delivers the motion for rotating the other spindle. I

For establishing a propelling relation between the intermediate drive-unit CAB- and the respective spindles, this invention embraces a first transmitting means conn prising a change spur-gear C meshing through two change gears o u with the change gear C, and a second transmitting means comprising a bevel-gear B meshing with the gear 13. In the embodiment of the invention depicted by Fig. 1, the gears C and B are secured to the ends of shafts 15 and i i which are positioned by widely spaced journals carried by the frame of the machine; one of said shafts extending paral lel to the direction of feed between the blank and the cutter, and the other one of said shafts extending parallel to the direction of adjustment in the oifset of the cutter to the axis of the work. This enables the respective spindles to be driven by anglegears 50 and m splined directly to said shafts. For example, the work-supporting spindle is driven by a worm-Wheel M which takes its motion from a worm m that is splined to the shaft 15 and thus permits the offset relation of the spindles to be adjusted for different diameters of teeth, by shifting the carriage 4 towards or away from the line of feed of the hob; With respect to the hob-spindle, the head 3 has suitable bracket'33 which journalsthe angle-gear m and causes it to slide on the shaft 14- (to which it is splined) and be kept in true mesh with the angle gear 3 of the unit y e wich is likewise journaled onthe'head 3 I transversely to the shaft 141; the. axis'of the unit y 6 being utilized as an off-set center of swivel for the hob bearing 30. It may be noted here that, since that center of swivel is off-set, the hob may not be swiveled through. such a wide range of angles as if the center of swivel had been conincident with the center of the hob and thus the range of the machine is to that extent restricted; but the advantages is that the construction is greatly simplified andrequires precisely the two gears extra required to balance the drive in combination with the same: number of two extra gears u and o employed. as extra change gears for materially extending the range of speeds of the Work relative to the cutter. In other words, the employ- ,ment of the two extra gears u and '0' is made possible without disturbing the balance of the drive of the spindles, by using also the two extra gears 00 and y, and conversely and thus not only is the speed range extended through the four change-gears C, a, o and C but the hob maybe disposed at various angles within a considerable range.

Thus it will be seen that,while the-Jen tire mechanism is balanced'as to driverand exhibits an extreme simplicity, nevertheless the range and adaptabilityof the ma, chine has been materially extended. JStarting with the initially-driven element of the transmission, each spindle drive is accomplished excluding. .mere. pivots or stubshafts .by six gears andone elongated shaft only thereby contributing. greatly to accuracy in mechanical assembly and steadiness and smoothness inaoperation through the balanced drive; Of theltotal number of twelve gears employed,.it is to'be noted that only two aresplined toslide on their shafts; the one being inthe 'onetra-nsmissiion and the other in the other transmission.

So far as the feeding .is concerned, no

great difficulty .has been experienced 'in se curing a high steadywadvance inasmuch as.

the motion is a relatively slow one. derived Irom a nut mounted n the sliding head and aconventional feed screw 10. As a'matter of convenience, the feed screw maypbe' rotated by a branch-line transmission located wherever desired, as for example, it may comprise the train of gears 16, 17 18,19,

20, 21Iand 22Qas will be understood. For preliminary adjustments, the hand-wheel N directly operating the bevel-gears 0 maybe used for turning the screw 10.

lowing combinationsand elements, or equivalents thereof, vbyfLetters Patent of the United States:.

1. A balanced-drive hobbing-machiiiecombiniiig a swivelable hob-supporting spindle and a work-supporting spindle; a transmission connecting said spindles'and consisting ofnotmorethan three long shafts, two of 'said shafts being arranged parallel to each other and transversely to one of said spindles, the adjacent ends of said two parallel shafts being directly connected by four change gears of the spur-tooth type, thethird shaft; of said 1 transmission beingarranged transversely to the hob-supporting spindle andbeing geared thereto by four angle gears; said third shaft being geared at its other end-"dire tly to; the intermediate one of said two parallelshafts;

a prime-mover geared directly to the intermediate shaft whereby the power for driv- I ing said spindles will be derived from the respective ends thereof; and'meaiis for effecting a. progressive relativie translation parallel 2. A balanced-drive combining a swivelable hob-supporting spindle and a work-supporting spindle arranged transversely thereto, a first long shaft arranged transversely tosai'd hobo-supporting spindle; aflast long shaft arranged trans-v versely to. said work-supporting spindle, the end of SaKl'fi ISt shaft being closely adjacent andcgeared tOtllB'lIOlJ-SUPPOITtlHg spindle by four angle gears, and the last shaft being geared to the work-supporting spindle'by two angle gears; anintermediate shaft 211-' ranged parallel, withPone of said transmission shafts; four intermeshing spur-gears, one secured directly 'to saidfintermediate :shaft, another directly to the transmission shaft parallel therewith; and meansfor effec'ting a progressive relative translation be- -.tween said spindles in a'directi on parallel with the worlosiipporting spindle. 'I 3..A- balanced-drive hobbing-machine combining a swivelmounted hob-support ing spindle and a laterally-shiftable worksupportingspindle, three shafts in series, the: first andthe third'being transverse to said spindles respectively, and the intermediate' second shaft being transverse to one of said shaftsandparallelwith the other shaft; six gears, .four of the spur-tooth type completing the transmission from the intermediate second shaft to the work-supporting sp ndle; six gears all of the angle-gea1 *'type completingthe transmission between the in termediate shaft and the hob-supporting spindle; andmeans' for effecting a progressive relative translation'between saidfspin- 4. A balanced-drive 1 bobbing-machine 1 combining a bedhaving a fixed stanchion;

a prime mover; 'an intermediate sha ft geared between 1. its ends directly to said primemover; an angle-gear mountedat one end of said intermediate shaft, and a. spur-gear mounted-at ltS' other'end; a hob driving 'lJIEIDSIIllSSlOD comprising a shaft and five angle-gears,=one of said angle gears ineshing directly with the angle-gear on said iuterinediate shaft; a work-driving transmission-comprising'a shaft and three spur gears l and two an'gle gears, one of said spurgears directly meshing'with the spur-gear on said intermediate shaft; andmeans for effecting "'a progressive feed of said head in a direction parallel 'with'the work-supporting spindle.-

5. .A balanced 'dr-ive bobbing-machine combin-ingfa' bed having-a fixed stanchion; {EJ162111 slidable thereon; ahob-supporting spindle sWivelly mounted on: said head; a carriage 'on -said bed; a Work-supporting spindle on said carriage; a three-shaft transmission connecting said spindles, two of saidshafts being arranged'parallel to each other and one of said parallelshafts being splined transversely tosaid work supporting spindle, the adjacent ends of said two parallel dies in a direction-;parallel with the workr supporting spindle. Having thus revealed this invention, I claim 'asnew and desireto securethe fol- Wvheel on said spindle meshing. with shafts being connected by four change-gears of the spur-tooth type; the third shaft of said transmission being splined, and arranged transversely to the other spindle and being connected by four angle gears to said other spindle and, at its other end, being connected by angle-gears directly to the intermediate one of said two parallel shafts; a prime-mover geared directly to the" intermediate shaft whereby power will be derived from its respective ends vfor driving said spindle-propellingshafts; and means for effecting a prcrgressive feed of said head in a direction parallel with the work-supporting spindle. r

6th hobbinganaehine coin bining shiftable head;-

angle=gear and a worm coan'ially jotn'nale-di on said head; a spindle. lTlOllnte'Cl on said head and swivelalo'le about the axis of said worm; a hob-supporting spindle ionrnaled in said mount; a wormsaid worni; a work-supporting spindle; a iirstsplined shaft arranged.transversely to said hob-supporting spindle; an angle gear spliiiefd to said shaft and meshing with said iirst rnentioned angle-gear; a second splined shaft arranged transversely to said worksupporti-ng spindle and connected by a worm and worna' wheel thereto; and an intermediate shaft arranged parallelwith said second shaft and connected at one end by bevel-gears directly to said first shaft; four v i spur-gears connecting the othe' end of said intei'rnaed-iate shaft with said second shaft;

- and nieans for effecting a progressive feed of said head in. a direction parallel with the work supportin g1 spindle. T

7. A balanced-drive hobbing-inacliine combining a' swivel-mounted hob-supporting spindle. and a work-supporting spindle a trans mission connecting said spindles and consisting in serial relation first of a set of tour angled gears,- secondof a pair of angledgears, third of a set of four spur-gears, and. fourth of a pair of angled gears and transmission shafts directly connecting each of said sets and pairs of gears inseries; a prime-mover connected to said transmission train between the one set and pair and the other set and pair, whereby the motion to the spindles will be transmitted intwobalanced-drive 12 ath's, the one being through the first set and pair of gears, and the other be. ing through the second set and pair of gears; and means for effecting? a progressive relative translation between said spindles in a.

balanced-drive bobbing-machine 'c'onibiningz a swivel-mounted hob' supporting spindle and work-supporting spindle; means for bodily shifting one or" said spindles in a direction transverse to the axis of-the other to adjnst the off-set relation between said spindles; a transmission connecting said spindles and consisting in serialrelation first of a set of four angledge'ars, second of a pair of angled gears, third of a set of four spur-gears; and fourth of a pair of angled-gears; transmission shafts directly conne'etingleach of said sets and" pairs of gears in the order named, oneof the first set of angle gears of said transmission being slidabl y shiftable on one of said 'sliafts said shaft being: arranged to extend in direction transverse to: the axis of the hob supporting spindle; and means for effecting aprogressive relative translation between said spindles in a direction parallel with the ,work-srtp-porting spindle;-

9'; A balanced-drivebobbing-machine combining a hob-supporting. spindle; and a work-supporting: spindle, worm-wheels on each spindle an intermediate shaft arranged transversely tosaid spindles,.an angle-gear mounted at one end of said shaft and a spur-gear detac hably secured directly to its other eird; and a second splined shaft arranged transversely to said spindles, respectively an angle gearcsecured to one end of said first splined shaft and meshing directly with said first mentioned angle gear; a detachable Spnr gear secureddirectly to one end of said second splined shaft; two coaXia-l'spnr gears in series with said detachable spur gearsran angle-gear spline'd to said first sh ft; twocoaxial angle-gears connecting: said angle gear with the worm wheel on said hob-supporting: spindle; a worm spl ined to said second spline'd shaft and meshing directly with the worm-whee] forpro'pelling saidiwork spindle; abed; a

slidable carriage supporting said workspindls; a slida-ble head; a niount for said hob-spindle swiveled to said head about the axis of said twocoaxial angle-gears; and means liior effecting: a progressive relative feed of said head in a direction parallel with saidworkspindle". I r i a In witness whereof,- I hereunto subscribe my name.

WILLIAM F. ZIMMERMANN. 

